A remote terminal unit (RTU) represents a device or system that provides localized control and data access at a site that is remote from a supervisory control and data acquisition (SCADA) system or other automation system. For example, multiple RTUs can be used at different sites and for different purposes in an oil and gas field. The RTUs can collect data, perform local control, record historical values using sensors and actuators at different sites (such as wells, pipelines, and compression stations), and provide live and historical data to a SCADA system. The SCADA system can execute control logic and alter the operations of actuators at the different sites via the RTUs. The RTUs themselves could also incorporate algorithms for data analytics.
In many conventional RTUs, the types of data inputs and data outputs available on the RTUs are fixed. While this typically enables conventional RTUs to be used in many different types of environments without modification, it can be a limiting factor in certain installations. For example, if more inputs or outputs of certain types are needed than are provided by a single RTU, multiple RTUs may be needed, which increases the size and cost of the installation.